cupoftea
Advanced Member level 5
Hi,
We are up for an offline PSU for 100-265VAC.
No-load-to-full-load transient will be very common.
Peak power is 400W.
Average power something like 50-250W.
(the downstream stage is wanted to be LLC)
At this power level....Is it really going to save that much doing a full totem pole PFC?...IE, with two GaN FETs and two SiC FETs.
They want it in a totally enclosed plastic enclosure.
Bridge rectifiers are tough...i reckon a bridge rectifier on a decent chunk of aluminium (with a plain old Boost PFC) might be just as small a solution as the totem pole PFC one?
Certainly the following tells that totem pole PFC with WBG devices gives just as big magnetics as plain old PFC...
I am just wondering that at 400W peak/ 250W average power, we would end up being nore efficient and small with a plain old BCM boost PFC?
I mean, the digital controllers needed for Totem pole PFC probably consume some 2W of power by themselves?
I dont see any totem pole PFCs with analog controllers....all micro controlled.....which means much bias power.
I reckon these 300W all-in-plastic chargers using totem pole PFC are all marketing hype?
Ive just searched for the datasheet for the NCP1680 CrCM Totem pole PFC controller, and you cant get it.....unless you email the distributor.......is this because they dont want people knowing about any high bias power draw that it may (or may not) have?
Page one of this says there are no analog controllers available for totem pole PFC as at 2017
We are up for an offline PSU for 100-265VAC.
No-load-to-full-load transient will be very common.
Peak power is 400W.
Average power something like 50-250W.
(the downstream stage is wanted to be LLC)
At this power level....Is it really going to save that much doing a full totem pole PFC?...IE, with two GaN FETs and two SiC FETs.
They want it in a totally enclosed plastic enclosure.
Bridge rectifiers are tough...i reckon a bridge rectifier on a decent chunk of aluminium (with a plain old Boost PFC) might be just as small a solution as the totem pole PFC one?
--- Updated ---
Certainly the following tells that totem pole PFC with WBG devices gives just as big magnetics as plain old PFC...
Utilizing Totem-Pole Bridgeless PFCs - Technical Articles
This article highlights ICERGi low-cost control and drive ICs simplifying totem-pole bridgeless PFC designs.
I am just wondering that at 400W peak/ 250W average power, we would end up being nore efficient and small with a plain old BCM boost PFC?
I mean, the digital controllers needed for Totem pole PFC probably consume some 2W of power by themselves?
--- Updated ---
I dont see any totem pole PFCs with analog controllers....all micro controlled.....which means much bias power.
I reckon these 300W all-in-plastic chargers using totem pole PFC are all marketing hype?
--- Updated ---
Ive just searched for the datasheet for the NCP1680 CrCM Totem pole PFC controller, and you cant get it.....unless you email the distributor.......is this because they dont want people knowing about any high bias power draw that it may (or may not) have?
--- Updated ---
Page one of this says there are no analog controllers available for totem pole PFC as at 2017
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